Process for coloring the surface of wood



' Patented Jan. 1, 1929.

TES

PATENT OFFICE.

MALCOLM SPABKES, OF LONDON, ENGLAND.

PROCESS FOR COLORING THE SURFACE OF WOOD.

No Drawing Application filed November The invention relates particularly to the colorin of the surface of wood by chemical action Instead of by liquid stain. woods with a strongly pronounced hard and soft grain the use of liquid stains produces an unsatisfactory and negative result, due to the soft portion of the timber absorbing most of the color while the hard grain is scarcely affected. 4 I

The invention has in view overcoming this difiiculty by giving a balanced coloring to both the hard and soft grain, thereby preserving and enhancing the natural color values. A,further object of the invention is so as to color inexpensive timbers that they may be raised to the front rank of decorative materials.

To these ends the invention primarily consists in treating the surface of the wood with a metallic sul hate and a developingreagent, and if desire with ammonia. The invention includes woods treated by thenew process.

The developing reagents may either be such as develop the color owing to the action of metal-containing salts, or be such as develop the color owing to a bleachin action.

Among the former reagents may h; men'- tioned the chromates, in particular, the bisurface of wood, consisting in treating the chromates and among the latter oxalic acid. The purpose of the developing reagent is to intensify or correct the effect produced by the effect of the metallic sulphate.

The metallic sulphate and developing reagent are employed in solution and the choice of the particular sulphate and whether the sulphate and the reagent are employed simultaneously or successively depend upon the particular wood'and the effect it is desired to obtain. The resultant tones may -be modified or improved b the addition of the ammonia which may e either in liquid or gaseous form.

Three examples of carrying out the process are, given below, but the invention is not limited to these examples:

Ewample 1 Oregon pine.

.880 liquid ammonia, and the moisture again evaporated. The result is a cool dark brown On all It is 21, 1925. Serial N0. 70,691.

color, which can be finished by wax polish, French polish or varnish.

Eat-ample 2 western hemlock.

Ewample 3 red cedar.

The surface of the wood is treatedwith a solution composed of 1 oz. of ferrous sulphate plus 4 oz. of potassium bichromate dissolved together in one gallon of water applied as before. When the moisture has evaporated the result will be a. warm nut-brown color,

which may be finished by wax polishing,

French polishing or varnishing.

I claim 1. A process for decoratively coloring the surface of the wood with a metallic sulphate and a developing reagent.

2. A process for decoratively coloring the surface ofwood, consisting in treating the surface of the wood with ferrous sulphate and a developing reagent.

3. A process for decoratively coloring the surface of wood, consisting in treating the surface of the wood with a metallic sulphate and a chromate. J

4. A process for decoratively coloring the surface of wood, consisting in treating the surface of the wood with a metallic sulphate and potassium bichromate.

5. A process for decoratively coloring the surface of wood, consisting in first treating the surface of the wood wlth a metallic sulphate and subsequently with a developing reagent and ammonia.

6. A process for decoratively coloring the surface of wood, consisting in first treating the surface of the wood with a solution including a metallic sulphate, evaporating the moisture from the treated surface, and then 3 surface of wood, consisting in first treating the surface of the wood with -a solution including ferrous sulphate, evaporating the moisture from the treated surface, and then treating the surface with a solution including a chromate mixed with liquid ammonia.

8. A process for decoratively coloring the surface of Oregon pine or wood of like character, consisting in first treating the surface of the wood with a solution including a metallic sulphate, evaporating the moisture from the treated surface, and then treating the surface with a solution including a chromate mixed with liquid ammonia.

9. A process for decoratively coloring the surface of Oregon pine or wood of like character, consisting in first applying evenly to the surface of the wood a solution including ferrous sulphate, evaporating the moisture from the treated surface, and then treating the surface with a solution including potassium bichromate mixed with liquid ammonia.

MALCOLM SPABKES. 

